Can worn guitar tubes cause the terrible noise issues from amp ?

Lux84

New member
When i got the amp, it's JCM 800 2204, with completly new tubes and anything, it doesn't hum that much, but now it's terrible. two months and a lot of playing hours, playing with attenuator and stuff.. it was allright, but now it just became terrible, because of to much hum, that don't go away even with good guitar cables, and even with Noise Gate pedal, in front, or in fx loop, all the same terrible hum... can be this because of worn tubes or something else inside the amp ? i think the noisse gets bigger day by day......
 
Re: Can worn guitar tubes cause the terrible noise issues from amp ?

Get it recapped , now.
BTW, cheap new production tubes need to be changed out once a year on a strict schedule. If you don't, and especially on a Marshall, you can take out the entire output transformer very easily when( not 'if" ) the tube shorts.
Once a year, change your tubes..more if you play more.If in doubt, change them out.
 
Re: Can worn guitar tubes cause the terrible noise issues from amp ?

If you don't have any spare tubes, get some spare tubes. Then start replacing the preamp tubes one by one. I think it's unlikely that it needs a new set of caps already. If it does, I'd have strong words with the manufacturer. I have been told and agree that most of the problems with tube amps come from the tubes. Power tubes are a bit trickier, because they require a rebias when they're replaced.
 
Re: Can worn guitar tubes cause the terrible noise issues from amp ?

If you don't have any spare tubes, get some spare tubes. Then start replacing the preamp tubes one by one. I think it's unlikely that it needs a new set of caps already. If it does, I'd have strong words with the manufacturer. I have been told and agree that most of the problems with tube amps come from the tubes. Power tubes are a bit trickier, because they require a rebias when they're replaced.

If that model number isn't a typo, the amp was made between 1981 and 1990 which may require a cap job depending on how heavily it was used / abused. Maybe try replacing the preamp tubes yourself, and if that doesn't work take the amp to a tech and have them check the power amp & filter caps.
 
Re: Can worn guitar tubes cause the terrible noise issues from amp ?

I'd get it checked out. Caps might be an issue, as well as the tubes. I don't think you need to change them every year, but definitely more often than you have. Especially using an attenuator a lot, this can wear tubes faster because you are still asking them to put out the higher wattage. The attenuator just siphons some off so it's not so dang loud. Take it to a reputable tech in your area.
 
Re: Can worn guitar tubes cause the terrible noise issues from amp ?

Yap, i have use the attenuator a lot. i will take it to a tech, to see where exactly can be problem there. i like that amp a lot from the beggining, so yes. :)
 
Re: Can worn guitar tubes cause the terrible noise issues from amp ?

Wait guys I think your all jumping the shark here... If i remember right this amp isnt a real JCM800 is a ceriatone amp kit right? Its brand new isnt it? It doesnt need caps. Its possible a tube or 2 went south... Try some spares if its still doing it take it to a tech
 
Re: Can worn guitar tubes cause the terrible noise issues from amp ?

If that model number isn't a typo, the amp was made between 1981 and 1990 which may require a cap job depending on how heavily it was used / abused. Maybe try replacing the preamp tubes yourself, and if that doesn't work take the amp to a tech and have them check the power amp & filter caps.

Not so fast they have been reissuing the JCM800 for the last couple years dont assume too hard on its age.
 
Re: Can worn guitar tubes cause the terrible noise issues from amp ?

Yap, it's a Ceriatone model... and i used a lot of attenuator, for about month. i also used half switch mode, so.. maybe it's tubes.

I have some other amp, Blackheart Handsome Devil which i used a lot in half way switch, and the tubes are already dead, after about half year of use only in triode mode.

I will never, ever again use any attenuator or half triode switch again. it seems that they just eats tubes like monsters ;)

However, talking about speakers with that amp.... i finally found out that G12-75's are the right ones for me.. because i play a lot of metal, and they seems to go better day by day.. and.. V30's and H30's i tried.. are nothing compared to those G12-75's with JCM to be honest ;)

I also have some more gain mod done by a tech, just before i get this new Ceriatone JCM 800 2204. and it don't need no boost pedals, nothing with those 75's speakers and that huge gain mod. at about preamp volume set at 4 to 6 of 10, i can talk about some serious metal zone, with huge low end :)

However i am happy with that amp, but.. want to reduce that unwanted noise.. because even the NS-2 turn up to full, don't really help to reduce that terrible bruuuuum that i am getting now for about three weeks now. it reduces it a bit, but not really well, so maybe there are some tube issues.

I will get that amp to a tech, definately, thanks :)
 
Re: Can worn guitar tubes cause the terrible noise issues from amp ?

Yeah jumping right to change the caps is pretty ridiculous.

Open up the back and tap the tubes or jiggle them a bit with the amp on. A microphonic or bad tube will make some pretty ****ty noises when you do this.

Using an attenuator will definitely eat tubes faster. And if this is a kit yo built yourself then there may be some other issues creeping up as well.
 
Re: Can worn guitar tubes cause the terrible noise issues from amp ?

What tubes are in it now, out of curiosity?

Tubes can introduce noise, certainly. Heck, I've seen amps that had the bias and tube matching off just a tick get a bit hummy.

Do the pencil eraser test on the preamp tubes. A lot of noise generates in the first couple gain stages of the preamp.

Sent from my DROID RAZR HD using Tapatalk
 
Re: Can worn guitar tubes cause the terrible noise issues from amp ?

Not so fast they have been reissuing the JCM800 for the last couple years dont assume too hard on its age.

The only JCM800 that's been reissued is the 2203, hence my remark about a typo. The amp was referred to only as a JCM800 2204 which was a Marshall amp made from 1976-1981 (in JMP guise) and then from 1981-1990 as a JCM800. That particular model has never been reissued.
 
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